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711.
湘西南震旦系是在“江口裂谷”作用下形成的一套特殊地层。长安组 (长安冰期 )、富禄组 (富禄间冰期 )和洪江组 (洪江冰期 )具有相同或相似的元素组合 (Cu、Pb、Zn、Co、Ni、V、Ti等元素组合正相关 )。他们的微量元素含量和主要组合特征对基底岩石 (高涧群 )具有继承性。从晚震旦世至早寒武世 ,元素Ag、As的相关模式基本相同 ,并且与元素Ba的相关模式曲线相似。还反映了大离子半径元素的热沉积的信息。V/Ni比值升高 ,Au、Ag趋向富集。说明晚震旦世晚期至早寒武世沉积盆地水体较深 相似文献
712.
人造金刚石是锯切石材最理想的材料。通过对锯片金刚石脱落及金刚石在废渣中赋存状态的分析,论述从废渣中回收金刚石的必要性、可能性和客观条件;利用金刚石特有的物理化学性质及其与造岩矿物之间的物性差异,采用筛分祛清洗废渣、矿物分离、金刚石提纯、选形分级等方法,可获得纯度为99%以上的人造金刚石,回收率可达10%一15%;通过对回收金刚石强度的测定和再利用,证明完全具有重新使用价值。从废渣中回收人造金刚石的方法可靠,工艺合理,成本约占产值的30%左右,具有较好的社会经济效益。在国内外属首创的回收入造金刚石方法具有良好的推广应用价值。 相似文献
713.
714.
Changhong Chen Yarong Peng Hongli Wang Qian Wang Shengao Jing Jingyu An Yaqin Gao Cheng Huang Rusha Yan Haixia Dai Tiantao Cheng Qiang Zhang Meng Li Jianlin Hu Zhihao Shi Li Li Shengrong Lou Shikang Tao Qinyao Hu Jun Lu 《环境科学学报(英文版)》2023,35(2):794-805
Both concentrations and emissions of many air pollutants have been decreasing due to implement of control measures in China, in contrast to the fact that an increase in emissions of non-methane hydrocarbons (NMHCs) has been reported. This study employed seven years continuous NMHCs measurements and the related activities data of Shanghai, a megacity in China, to explore evolution of emissions and effectiveness of air pollution control measures. The mixing ratio of NMHCs showed no statistical interannual changes, of which their compositions exhibited marked changes. This resulted in a decreasing trend of ozone formation potential by 3.8%/year (p < 0.05, the same below), which should be beneficial to ozone pollution mitigation as its production in Shanghai is in the NMHCs-limited regime. Observed alkanes, aromatics and acetylene changed by +3.7%/year, -5.9%/year and -7.4%/year, respectively, and alkenes showed no apparent trend. NMHCs sources were apportioned by a positive matrix factorization model. Accordingly, vehicular emissions (-5.9%/year) and petrochemical industry emissions (-7.1%/year) decreased significantly, but the decrease slowed down; significant reduction in solvent usage (-9.0%/year) appeared after 2010; however, emissions of natural gas (+12.6%/year) and fuel evaporation (with an increasing fraction) became more important. The inconsistency between observations and inventories was found in interannual trend and speciation as well as source contributions, emphasizing the need for further validation in NMHCs emission inventory. Our study confirms the effectiveness of measures targeting mobile and centralized emissions from industrial sources and reveals a need focusing on fugitive emissions, which provided new insights into future air policies in polluted region. 相似文献
715.
Hua Li Lin Cao Rong Sun Wenyi Dong Hongjie Wang Zhongyi Dai Xue Wang Jin Xie 《环境科学学报(英文版)》2023,35(2):758-768
To achieve advanced nitrogen removal from actual municipal sewage, a novel multistage anoxic/aerobic process with sludge regeneration zone (R-MAO) was developed. The reactor was used to treat actual domestic sewage and the nitrogen removal capacity of the sludge regeneration zone (R zone) was investigated during the long-term operation. The best performance was obtained at the R zone's Oxidation-Reduction Potential (ORP) of -50±30 mV and hydraulic residence times (HRT) of 1.2 hr. The average effluent COD, TN, NH4+-N and NO3−-N of the R-MAO process were 18.0±2.3, 7.5±0.6, 1.0±0.5 and 4.6±0.4 mg/L, respectively, with the corresponding removal efficiency of COD, TN and NH4+-N were 92.9%±1.0%, 84.1%±1.5% and 97.5%±1.1%. Compared to the sole MAO system, the TN removal efficiency of the R-MAO increased by 10.1%. Besides, under the optimal conditions, the contribution of the R zone in the R-MAO that removal COD, TN, NH4+-N and NO3−-N were 0.36, 0.15, 0.032 and 0.82 g/day. High-throughput sequencing results showed that uncultured_bacterium_f_Burkholderiaceae (5.20%), OLB8 (1.04%) and Ottowia (1.03%) played an important role in denitrification in the R zone. This study provided effective guidance for the design and operation of the R-MAO process in domestic sewage treatment. 相似文献
716.
对有机垃圾成分,热力特性和焚烧所产生的二次污染的研究,证实了:我国城市有机垃圾热力处理法在技术上是可行的。 相似文献
717.
根据上海市新一轮环保三年行动计划(2006~2008年)要求,上海将在未来3年中完成全市11家电厂的35台约6508MW燃煤发电机组的烟气脱硫工程,这同时将产生大量的烟气脱硫副产品——脱硫石膏,处置和利用好脱硫石膏,对上海市的生态环境保护有着重要的意义。阐述了燃煤电厂烟气脱硫石膏的特性和国内外脱硫石膏的利用现状。结合上海实际,对烟气脱硫石膏在建筑建材业.农业等领域的应用前景进行了分析。指出烟气脱硫石膏的资源化利用符合循环经济理念,并能产生良好的环境、社会和经济效益。提出了烟气脱硫石膏的利用建议。 相似文献
718.
The thermodynamic relationships among aqueous solubility and molar volume (MV) , total molecular surface area (TSA) and molecular connectivity index (MCI) for highly hydrophobic chemicals. PCBs are established and discussed, respectively. Good linear relationships exist among In Cs and MV, TSA or MCI. 相似文献
719.
取代芳烃对酵母菌毒性的定量结构-活性相关研究 总被引:3,自引:0,他引:3
定量测定了苯胺类、苯甲酸类、卤代苯类、苯腈类、硝基苯类、苯酚类等6类化合物对酵母菌的生长抑制毒性,结果表明化合物的最小产生清晰抑菌圈浓度C_(miz)与辛醇-水分配系数及一阶分子连接性价指数有如下关系:log(1/C_(miz))=0.38logK_(ow)+0.33 ̄1X ̄v-0.38r=0.92s=0.22n=77.在上述6类取代苯类化合物中,它们与酵母菌的反应性大小有如下顺序:卤代苯类≈苯甲酸类<苯胺类<苯腈类<苯酚类<硝基苯类化合物;用Free-Wilson法研究各基团对酵母菌毒性的贡献大小,其顺序为:—Br(0.84)>—Cl(0.54)>—CH_3(0.39)>—NO_2(0.35)>—COOH(0.19)≈—OH(0.17)≈—CHO(0.17)≈—CN(0.14)>—F(—0.03)>—NH_2(—0.08).苯胺类、苯腈类、苯酚类、硝基苯类化合物对酵母菌的毒性与化合物的分子连接性指数3Xv、4X、3X有良好的相关性. 相似文献
720.